Friends reunited.

The following review contains spoilers for the latest episode of Sherlock: "The Lying Detective."

While "The Lying Detective" is a much stronger and far more sinister outing for Sherlock than last week’s underwhelming season premiere, it’s still hampered by another unsatisfying case and some odd story beats. Thankfully, there were also some strong performances and a brilliant reveal that sets the show off in an intriguing new direction.

The episode opens with a frantic 30 minutes in which not a lot happens – John sees a therapist and mourns the death of Mary, while Sherlock, wracked with guilt, withdraws from society and takes comfort in the arms of an old friend (heroin). (He also suddenly has a drug dealer who lives in his kitchen.)

While I'm sure it's breathless pacing and style meant to be mirroring Sherlock’s drug-induced mania – some of the stylistic choices owe a debt to Trainspotting – after thirty minutes it becomes tiresome. There’s not a scene that isn’t cluttered by a visual effect, voice over, flashback, playful transition, or hallucinatory character, which becomes something a recurrent motif in this particular episode. Eventually, it all becomes too much, with the maniac pace and style undercutting the drama. Key moments just aren’t allowed to play out and breath – John's grief, Sherlock's guilt – since the show is travelling as fast as Mrs Hudson in her Aston Martin.

The breathless first act sees Sherlock visited by the daughter of Culverton Smith (Toby Jones), a famous British entrepreneur and philanthropist. She tells Holmes about a bizarre meeting three years ago in which her father confessed to his inner circle that he was about to kill, but he did so while they were connected to drips containing a drug that would eventually erase all memory of his criminal confession. She managed, however, to transcribe some of the key details, and asks Sherlock for his assistance to find out who was murdered.

Holmes quickly concludes that her father hasn’t killed a single person but is, in fact, a serial killer. And in an effort to stop him, Holmes makes his sensational conclusion public. Smith kindly requests the detective's company, and the rest of the episode sees Holmes shadowing Smith, as he shoots an advert for his latest breakfast cereal and pays a visit to a hospital he helped build.

Since Sherlock is clearly in a bad way, and distracted by his rekindled habit, I guess there's meant to be some degree of dramatic uncertainty as to whether Sherlock is mistaken and has accused an innocent man, but in truth, there's never any doubt around Smith. Not only does he have a mouth full of twisted teeth like a shark, he’s clearly based on a real-life monster – with his charity runs and habit of freely wandering hospitals he helped build, he’s obviously based on the unsavoury crimes of Jimmy Saville. A grotesque scene set in the morgue underscores the allusion and removes all ambiguity. Jones serves as a great, scenery-chomping monster, really making the most of the outlandish character he’s been given.

But because Smith's guilt was always so evident, there’s little satisfaction to be had when he's eventually caught by Sherlock. It feels inevitable. Even the ‘twist’ – that despite appearing compromised in a hospital bed, Sherlock is still one step ahead of Smith – doesn’t work, because Sherlock has spent the entirety of the episode being utterly brilliant while under the influence. In fact, it’s a recurring gag throughout "The Lying Detective" that despite being ‘off his tits’, Sherlock is still capable of uncannily predicting the actions of those around him, sometimes weeks in advance. So his crafty entrapment of Smith doesn’t register as a surprise, since it’s entirely consistent with his brilliant behaviour shown earlier on.

In fact, we eventually learn the whole thing has been a ruse. We discover that Sherlock relapsed and deliberately pursued a psychopath because Mary, John's recently deceased wife, told him to place himself in danger to get John's attention and mend their friendship. Even in a world occupied by sociopaths fascinated with elaborate psychological games, Mary's posthumous request seems unnecessarily complex. It's too overwrought, and ultimately dramatically it gets in the way of them tackling the situation head on. One of the best scenes in the episode is when John has to disarm Sherlock, who is threatening Smith with a scalpel. John unleashes the rage that has derailed their friendship, and gives Sherlock a vicious beating. It's a great scene, and left me wishing they had more time on screen working through these problems and emotions. Instead, the show seemingly wants to keep them apart and manoeuvre them within increasingly convoluted plots.

But there were some genuine and effective surprises to be had, too. Just when you think the episode has fully unfolded, there’s an additional twist: the existence of a third Sherlock sibling, Eurus, and it turns out, she's been deceiving Holmes and Watson (and us) throughout the season. It turns out that Watson’s weird flirty text subplot from last week was part of the set-up, with Eurus revealed as the mysterious woman on the bus, while in this episode she impersonates Culverton’s daughter and, in the process, manages to fool Sherlock, firmly establishing her as a formidable adversary.

The Verdict

With one episode of season four to go, it feels like Holmes and Watson’s relationship has finally been restored. The introduction of the mysterious and dangerous Eurus feels like a bold direction in which to take the final episode. Her methodical unmasking in front of John was a definite highlight of the season so far, and I’m looking forward to learning more about the character and her fractious history with the Holmes brothers.
At the same time, it feels less likely that the Moriarty cliffhanger of three years ago will be adequately addressed, but here’s hoping that next week’s episode can capitalise on its intriguing new villain and end the season on a high.